Updated: 7:23 PM EDT May 10, 2021 The Associated Press Serene, stark and seemingly in the middle of nowhere in Pennsylvania, the National Park Service memorial to the people who died on United Airlines Flight 93 is hard to find on a map as the Sept, 11, 2001, terrorist attack itself slips deeper into the nation’s collective memory.And even schools that do teach about the day may only bring it up only on the anniversary, rather than as a point in a long arc of history and a turning point that left the U.S. irrevocably changed, 20 years later.Families of Flight 93′s 40 passengers and crew members are trying something new to change that: an annual award for heroism. Nominations open Monday through the nonprofit group, Friends of Flight 93 National Memorial.The award aims to reward selfless acts of heroism, but also to educate the public on what happened when those aboard the hijacked plane, bound for San Francisco, discovered that jets had been flown into